[clang] [flang] [lldb] [lld] [libcxx] [mlir] [compiler-rt] [clang-tools-extra] [llvm] [DWARFLinker][NFC] Decrease DWARFLinker dependence on DwarfStreamer. (PR #77932)

[Jonas Devlieghere via cfe-commits]

https://github.com/JDevlieghere approved this pull request.

Before this patch, the DWARFLinker was the one responsible for creating the streamer, which meant that both the classic and parallel implementation needed to conform to the same interface. After this patch, the concrete implementations instantiate their own streamer, which means that the classic linker can support the Swift sections while the parallel implementation can ignore them for now. 

Makes sense to me. LGTM! 

https://github.com/llvm/llvm-project/pull/77932